As the great powers maneuver and threaten, Syria burns. It is a historic tragedy that threatens the fragile ties that have bound a fraying network of diverse peoples in an age-old civilization.

That President Bashar Assad’s government now finds itself in the position of defending an ancient Christian community against attacking Islamist rebels is an irony that might twist Westerners in knots. What side are we supposed to be on?

We are not supposed to be on the side of poison gas, though we have been on that side before, as when the Reagan administration ignored Saddam Hussein’s use of gas against Iranians and Kurds.

Now Assad has used poison gas against fellow Syrians, and the Obama administration is trying to persuade Congress to authorize a retaliatory strike by American forces.

That he has involved Congress in the debate was either deeply mistaken or deeply correct. If quick action was needed, it would have been best to steer clear of Congress’ paralysis and dysfunction. But if public support is important, then getting support from Congress might at least enlist the legislative branch in persuading the public that an attack on Syria is justified.

Sens. Patrick Leahy and Bernard Sanders and Rep. Peter Welch are not yet persuaded. The foolish adventures of the last decade, as well as the difficulties in Afghanistan, have left them with a bitter taste about military campaigns in the Middle East and Asia.

At the same time, they are three members of Congress who are especially sensitive to the demands of human rights, and they are not likely to look away at the depredations of dictators such as Assad. Nor should they.

One reason to remain wary of action in Syria is that U.S. attacks inevitably radicalize part of the Muslim world, even when those attacks are justified, as in Afghanistan. In some respects we cannot help but make things worse when we land with big feet among Muslim peoples. Our wars in Afghanistan and Iraq have helped created new generations of jihadis. Whatever side we are on, we are making enemies of someone. (See: Egypt.)

Now the Russians and the Syrians are holding out the possibility that intervention might be avoided. Syria has agreed with a Russian plan to put its chemical weapons under international supervision. The Obama administration immediately warned that the plan might be a stalling tactic. It would most certainly become a protracted cat-and-mouse game between the Assad regime and international inspectors. But it puts the onus on Assad never to use chemical weapons again.

The offer comes at a time when Obama’s bid for support faces uncertain prospects in Congress. Congress would be well advised to strengthen Obama’s hand by passing a resolution authorizing an attack if Syria reneges on promises to give up its chemical weapons. The United States would be securing a gain by putting those hideous weapons out of bounds and establishing that Assad is a pariah for having used them.

It is unclear whether the proposal will survive even a day as high-stakes diplomacy runs its course, involving the French, among others. But Obama is right to force the issue on chemical weapons.

Meanwhile, the war continues in Syria, and the Middle East appears to be entering a phase of tragic loss. Built into the logic of every tyranny are the elements of its own undoing, and the nations of the region have had a long history of tyranny.

Now subject peoples are struggling to breathe free, even if their causes do not promise freedom for everyone.

For Islamic radicals, freedom is the freedom to do it their way. The liberal dream of a pluralistic society, where Sunni lives peacefully next to Shia, Muslim next to Christian and Jew, is cowering in the shadows of the old marketplaces, where the shrapnel is flying.

A few rockets launched by America are not going to redeem that dream, though they could remind Assad that the world is watching and he will have to pay a price for his ruthlessness.